an ellipse with foci at (-6,4) and (0,4); major axis length is 10. what is the standard form?

The center will be at (h,k) =  (-3,4)

a  = 5

c = 3

And  b  = sqrt (a^2 - c^2) =  sqrt (5^2 - 3^2)  = sqrt ( 25 - 9)  =  sqrt (16)  =  4

And the equation is

(x - h)^2 / a^2  +  (y - k)^2 / b^2   = 1

(x - -3)^2 / 25 + (y - 4)^2/ 16   = 1

(x + 3)^2 / 25  +   ( y - 4)^2 / 16  =  1

Here's the graph :